{"product_id":"catalytic-converter-for-gmc-c-k-trucks-1996-1999-5-7l","title":"Catalytic Converter for GMC C\/K Trucks (1996-1999) 5.7L","description":"\u003ch2 style=\"font-size: clamp(18px, 3vw, 21px); margin-bottom: 15px; line-height: 1.3;\"\u003eDirect-Fit Catalytic Converter Assembly for 1996-1999 GMC C\/K Trucks (GMT400)\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat it Does:\u003c\/strong\u003e The catalytic converter assembly replaces degraded or blocked factory converters on 1996-1999 GMC C\/K Trucks to restore proper exhaust scavenging, eliminate excessive backpressure, and resolve emissions trouble codes.\u003c\/p\u003e\n\n\u003ch3\u003eThe Stock GMC C\/K Trucks Substrate Degradation\u003c\/h3\u003e\n\u003cp\u003eWith decades of operational heat cycles, the factory emissions hardware on \u003cstrong\u003eGMT400\u003c\/strong\u003e trucks routinely suffers from fractured ceramic washcoats, core melting, and carbon fouling caused by high-mileage oil blow-by or rich air-fuel mixtures. Over time, physical substrate breakdown restricts flow inside the dual-inlet collector pipe, driving up exhaust gas temperatures (EGTs), choking the top-end volumetric efficiency of the \u003cstrong\u003eVortec 5700 L31\u003c\/strong\u003e engine, and triggering persistent P0420\/P0430 catalyst efficiency DTC faults.\u003c\/p\u003e\n\n\u003ch3\u003eThe Engineering Solution\u003c\/h3\u003e\n\u003cp\u003eThis direct-replacement exhaust assembly is manufactured from heavy-wall stainless steel tubing coupled to a high-density ceramic honeycomb monolith. Wash-coated with premium noble metal catalysts (platinum, palladium, rhodium), it restores closed-loop stoichiometric conversion efficiency while maintaining smooth, low-restriction laminar exhaust flow. Precision-bent downpipes match factory routing and incorporate pre-welded oxygen sensor ports and thick OE-profile flanges, providing a leak-free bolt-on installation without cut-and-clamp fabrication. Interchangeable with OEM part numbers \u003cstrong\u003e645328\u003c\/strong\u003e, \u003cstrong\u003e50239\u003c\/strong\u003e, and \u003cstrong\u003e50410\u003c\/strong\u003e.\u003c\/p\u003e\n\n\u003ch3\u003eTechnical Specifications\u003c\/h3\u003e\n\u003cdiv style=\"overflow-x: auto; margin-bottom: 20px;\"\u003e\n  \u003ctable width=\"100%\" style=\"border-collapse: collapse; border: 1px solid #e0e0e0; font-size: 14px; min-width: 300px;\"\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eFitment\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e1996-1999 GMC C\/K Trucks\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eEngine \/ Chassis\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e5.7L Vortec L31 V8 \/ GMT400\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr style=\"background-color: #f9f9f9;\"\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eStock Output\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e250 hp \/ 335 lb-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth style=\"padding:10px; text-align: left; border: 1px solid #e0e0e0;\"\u003eReplaces OEM Part #\u003c\/th\u003e\n\u003ctd style=\"padding:10px; border: 1px solid #e0e0e0;\"\u003e645328, 50239, 50410\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\u003c\/div\u003e\n\n\u003ch3\u003eCompatibility\u003c\/h3\u003e\n\u003cul\u003e\n  \u003cli\u003e1996-1999 GMC C1500 5.7L V8\u003c\/li\u003e\n  \u003cli\u003e1996-1999 GMC K1500 5.7L V8\u003c\/li\u003e\n  \u003cli\u003eFits 1500 series half-ton models only; does not fit 2500 or 3500 series\u003c\/li\u003e\n  \u003cli\u003eEPA compliant (46-state legal; not legal for sale or use in CA, NY, CO, or ME)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eFrequently Asked Questions\u003c\/h3\u003e\n\u003ch4\u003eDoes this fit the GMT400 C\/K Trucks?\u003c\/h4\u003e\n\u003cp\u003eYes, this is a direct fit for the 1996-1999 GMC C\/K Trucks equipped with the Vortec 5.7L L31 engine.\u003c\/p\u003e\n\n\u003ch4\u003eWill installing this unit resolve active catalyst efficiency check engine lights?\u003c\/h4\u003e\n\u003cp\u003eYes, assuming oxygen sensors and upstream engine management are operating within factory tolerances, this unit restores standard emissions efficiency to clear P0420 and P0430 fault codes.\u003c\/p\u003e\n\n\u003ch3\u003eThe GMC Heavy-Duty Durability Standard\u003c\/h3\u003e\n\u003cp\u003eConstructed to endure demanding payload hauling and high-load towing cycles, this heavy-duty stainless assembly resists road salt corrosion, extreme thermal shock, and frame-twist vibration encountered on rugged job sites.\u003c\/p\u003e","brand":"VelocityMax","offers":[{"title":"Default Title","offer_id":67537758814456,"sku":"DS-EVDN2PN5G","price":215.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0800\/1290\/2648\/files\/catalytic-converter-for-gmc-c-k-trucks-1996-1999-5-7l-1.jpg?v=1790617045","url":"https:\/\/performancechiptuning.com\/es\/products\/catalytic-converter-for-gmc-c-k-trucks-1996-1999-5-7l","provider":"Performance Chip Tuning","version":"1.0","type":"link"}